In 2008 Anne Harfenist completed her second year of a survival study of Leach’s Storm-petrels (Oceanodroma leucorhoa) on Cleland Island in the Cleland Island Ecological Reserve. The field work took place on July 2-3, 2008, and involved one biologist and one field assistant.

In 2009 Anne Harfenist completed her third year of a survival study of Leachs Storm-petrels (Oceanodroma leucorhoa) on Cleland Island in the Cleland Island Ecological Reserve. The field work took place on July 1-3, 2009, and involved one biologist.

Leach’s Storm-petrel survival in British Columbia (Jul 2007) Author: Harfenist Environmental Consulting; Harfenist, A.
In 2007 Anne Harfensit completed the first year of a survival study of Leachs Storm-petrels (Oceanodroma leucorhoa) on Cleland Island in the Cleland Island Ecological Reserve. The field work took place in 2.5 days, July 6 -8, during which time one biologist and one field assistant banded 300 Leachs Storm-petrels.

As upper trophic level predators, marine birds are considered useful indicators of changes in marine ecosystems (eg. Furness and Camphuysen 1997; Boyd and Murray 2001). Much seabird research has examined reproductive parameters and population trends of species representing a range of feeding guilds in relation to oceanographic conditions (eg. Ainley et al. 1995). Over the last decade, the emphasis has shifted to incorporate adult survival estimates (eg. Bertram et al. 2005; Sandvik et al. 2005) – a key demographic parameter for long-lived species with low annual reproductive output such as seabirds.

Storm-petrels (Oceanodroma sp.) comprise approximately 27% of British Columbia’s total population of nesting seabirds (Rodway 1991). Their feeding habitat and primary prey species differ from those of other seabird species in the province: they forage over the shelf break and open ocean on prey items caught on the surface including myctophids and amphipods (Vermeer 1992). Despite their abundance and significance as indicators of conditions in portions of the marine ecosystem that are difficult to otherwise study, population trends and demography of storm-petrels in B.C. remain poorly described. Furthermore, their feeding habits render storm-petrels especially vulnerable to offshore oil and gas development. Baseline survival estimates will be required for impact assessment if offshore exploration proceeds in the future.